Who is making these decisions to rewrite?
It would be great if we can see a before and after comparison.
Clojure is a pretty simple language. Ive taught it to junior devs with only Java experience and they learn it within a few weeks without any major problems.
So every hire will be a cost to cross train through language as well as get used to the codebase. And a lot of more seasoned devs are very binary about lisps. I personally wouldn't work at a place that wanted me to do Clojure over Scala/Java/Kotlin.
I worked at a globally known media company that were primarily a Scala company and they had made a handful of applications from people with Scala experience a year at best. The churn of every skilled dev leaving being replaced by someone very green is a horrible opportunity cost even for a large business.
Even training devs isn't an issue. C#, Java, Python, PHP, C, JavaScript, and Ruby developers have had an easy time being productive on the first day because of how high level the language is. Projects tend to be very domain-driven, and a decent editor config let's people get started right away. Within a week of reading code and a tutorial on syntax, I have a perfectly reasonable dev on my team making meaningful contributions to maintenance and feature development. Locality, immutability, and brevity make for an exceptionally fast on boarding experience even when the dev had never used clojure or a lisp before.
(I remember my boss at one of my previous jobs literally saying to me "you know, we could let you write that in something more advanced, like Ruby or Python, but then when I'll be hiring, I'll have to pay 2x to a Ruby programmer than I have for a PHP programmer, so PHP it is".)
Shortsightedness is not a new invention.
I have plenty of anecdata for when I invested in a better tech fit without asking anybody and it always ended up great. EVERY. SINGLE. TIME. I got a few slaps on the wrist because managers don't like not controlling how you breathe but even they were forced to admit that I saved them money in the mid- and long-term.
I am getting old and cynical and quite frankly I never ask business people questions I know the answer to anymore. I also don't go fanboy mode about languages and tech anymore. If I find a better alternative for something that keeps bleeding my employer's money and human resource with no end in sight, I'll switch it over on both technical and long-term cost-saving merit.
To hell with anyone who disagrees. My stance these days is -- "I know both programming and some business. You only know business. I am better equipped to make the decision than you."
--
Related: I sometimes wonder just how much money companies lose on trust issues. Even with regular people, I often see companies spending money doing everything imaginable to make it as difficult as possible for workers - on which, too, they spend money - to do their jobs.
It only goes downhill for these companies and they lack the maturity and intelligence to recognize they brought it upon themselves and maybe start trying to turn things around.
Oh well, screw them.
Fine, it wasn't 100% clear: "it ended up being great every single time". By saying that I didn't mean that I got tingles in my stomach for using some tech, I am saying that I helped an employer stop bleeding money and human resources in a black hole.
Today I would love to start a project in Elixir/Phoenix (or more realistically: Python/Django), but I don't know any Elixir devs in Berlin. And I don't know too many web devs using Django in Berlin. Again if I had to build a static website, I would choose PHP (+ Laravel framework). And if it was a dynamic web app, I'd choose Node+React. It's all about availability and feasibility.
Edit: punctuation
(1) You keep saying you didn't know technology X or Y devs in Berlin. Sorry to partially derail but why is remote forbidden in your organization? I mean, you're pointing at a limitation that's rather easy to overcome.
(2) Bigger developer availability == good for business, you claim. That's very 50/50, neither side of this argument is anywhere remotely universally correct. "If all you know are hammers all problems look like nails". I've had PHP devs ruin near-perfect projects in teams where I was working. Their reliance on the arcane-but-overall-working comparison operator alone introduced at least 150 bugs over a year.
Bigger dev pool != better for business. It just helps you treat people like replaceable cogs in a bigger machine. That's not the same thing at all.
(3) Known tech != quick onboarding. You yourself pointed out your new hires needed to learn Symfony. And you claim to be interested in Elixir and Phoenix. Well, for one thing, Elixir is extremely easy to learn as a language; secondly, it's OTP (the Erlang / Elixir concurrency framework) that's hard.
So what you said could absolutely apply to Elixir. The language is learned extremely quickly and then people have to spend some time getting to know a framework. It's the same everywhere really.
I feel your comment was putting too much weight on local physical availability of programmers and that's the wrong metric to use when assessing new (and possibly better) tech.
Also, even if the funding was better: One important aspect is: What if key developers (in that fancy new technology) leave the project? How fast can you find new devs? If it is a widespread technology (say: Node/Express + React) there is no risk. But think of hiring Erlang developers in your region.
I like Scheme (and it's influence on JS), I love functional programming, I like Ruby a lot, I really love Elixir. I like Python and Django a lot. But when it comes to setting up a project there are many aspects that determine my decision for technology. Some very important ones: What are my tech alternatives to tackle a problem? How wide spread is that technology in my region? How fast can I hire talented people in that tech?
I do acknowledge that a small team of good Python+Django devs for instance can work more efficiently than a team of PHP devs who don't appreciate software engineering qualities (not saying that there aren't really profound PHP devs out there, but many PHP devs who don't have profound software engineering qualities). There are only three real alternatives for web dev in Germany (if you have a tight budget): PHP based, Node/Express+React/Angular or Ruby/Rails based. I wouldn't even consider Python/Django, and forget about Elixir/Phoenix.
I was talking about you bringing in remote Elixir talent. It's not so hard nowadays, the dev base is growing.
So no, I disagree. Known language is not quicker onboarding for a framework. You'll save 4-10 workdays out of the several dozens needed for one to become an expert in a framework.
It grinds my gears to hear that legend over and over -- "new language is very risky and slow to adopt!", even though a lot of us know that the language itself is the lowest barrier of all.
On top of framework and codebase I'd also add organizational or team coding style. It becomes a bloody mess pretty damn quickly. I've personally spent 6 months being onboarded in a very finely tuned and hacked to oblivion Rails project -- a technology I knew pretty damn well at the the time -- and then it took me 3 weekends to get my own Elixir / Phoenix project off the ground... and for it be useful in business terms as well.
So these "new language risks" are vastly overstated and are simply an excuse for dogmatic people to not act in the project's best interest.
This is one of the most unforgettable lessons I've learned in life-- 90% of the dev hiring market is between 4 languages: Java, Python, Javascript and C.
Beyond this it barely matters how awesome your language is. The manager at the other end is optimizing for per person cost, and trying to hire as many people as he/she can.
Leaving this comment so people who may read this and get scared off understand that it's definitely not the case.
My company has both a) hired a number of Clojure developers, and b) a number of developers who were good programmers, so switching to Clojure was not a problem.
In general, I noticed that you either hire average programmers (in which case Clojure/ClojureScript could be a problem), or good programmers. Good programmers have no problem with Clojure, regardless whether they know it or not.
Leaving this here because people might think the above comment is universally true. It isn't.
Meanwhile, Scala is a much more complex language, and training somebody on it will be a lot more challenging.
But if I had to take an average Java programmer and teach them a new language choosing between Clojure and Scala, I’d choose Scala hands down. The gap in semantics is so much closer, and concepts and libraries are so much more easily translatable. And it is entirely possible to be productive with Scala while knowing <50% of the language.
Meanwhile, my team regularly hires coop students, and we never had to spend more than a couple of weeks training them to be productive in Clojure. Hiring and training people is simply not a real world problem when it comes to Clojure.
With Scala you can start out in better java territory and go from there to wherever you want. I personally don’t use any of the pure functional libraries, but I still greatly benefit from the strongly and strictly typed but flexible type system. In the 50k+ lines on my most recent project, I can count the number of bugs that escaped the type checker with one hand.
How big of a problem this is depends on the team and the company.
I've worked on plenty of medium (30+ dev) projects with <10% yearly turnover and for these teams learning Clojure is practically no cost.
I've also worked on teams with 70%+ yearly turnover and teaching anyone anything was a waste of time.
Media companies tend to be on the higher turnover side and I wouldn't recommend Scala or Clojure.
I was on a major automation project where mgmt nailing down the specifications across four existing departments procedures took over a year... hard to imagine devs working less than a year making sense of it.
Anecdotal evidence incoming: For any rewrite it's always the developer. Every time. It might sometimes be the manager's decision to do it, but it's always instigated by a developer.
It's similar to training someone to use Vim in that it's quite a different tooling set and workflow they're probably used to. I think that's the main barrier.
The language itself is pleasantly simple. And tools like Paredit make it one of the most pleasant languages to write. It's just hard for someone to appreciate Clojure until they put in the work to credentialize in its tooling.